Quadruples of different integers from [ 2,n ] with no common factors between pairs.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =2a(6) =3a(7) =6a(8) =6a(9) =26a(10) =27a(11) =72a(12) =79a(13) =90a(14) =109a(15) =228a(16) =238a(17) =431a(18) =461a(19) =523a(20) =565a(21) =928a(22) =963a(23) =1255a(24) =1349a(25) =1597a(26) =1697a(27) =2499a(28) =2534a(29) =3571